Pixellated WDM optical components

Abstract

A micromirror array is used to form optical apparatus useful in WDM optical networks. In one embodiment, the micromirror array is used to insert a desired attenuation in individual channels for purposes such as equalization. In another embodiment, the micromirror array is used to form an optical monitor useful as an optical spectrum analyzer.

What is claimed is:  
     
       1. Apparatus for inserting a controlled amount of attenuation in the power level of individual channels of a wavelength-division-multiplexed optical signal comprising: 
       a panel comprising a plurality of micromirrors that can be selectively tilted either to or not to reflect the incident light in a direction for recombination into the output beam, the plurality of micromirror being arranged in a two-dimensional array essentially a plurality of rows and a plurality of columns with at least one column exclusively for each channel of the signal and each column including a plurality of micromirrors, corresponding in numbers to the output levels to be provided;  
       means positioned to intercept an input wavelength-division-multiplexed input beam for separating the beam into individual channel beams, for directing the separate beams for incidence on separate columns of the micromirrors of the panel, and for recombining into the output beam the separate beams reflected in the desired direction; and  
       means for controlling the number of micromirrors in each column tilted away from the direction for recombination into the output beam to control the attenuation inserted.  
     
     
       2. The apparatus of claim  1  in which each micromirror can either reflect incident light in the desired direction for recombination or scatter it. 
     
     
       3. The apparatus of claim  1  in which the means to intercept the input wavelength-division-multiplexed beam is a diffraction grating. 
     
     
       4. The apparatus of claim  1  in which the means to intercept the input wavelength-division-multiplexed beam is an arrayed-waveguide-grating router. 
     
     
       5. The apparatus of claim  1  in which the means to intercept the input wavelength-division-multiplexed beam is a prism. 
     
     
       6. The apparatus of claim  1  in which each column includes at least hundreds of micromirrors and each channel beam is made incident simultaneously on a plurality of micromirrors of a column. 
     
     
       7. The apparatus of claim  6  in which the means positioned to intercept the input wavelength-division-multiplexed signal spreads each channel beam a uniform amount in the direction of the columns. 
     
     
       8. The apparatus of claim  1  in which each channel beam is incident on a separate group of a plurality of columns of micromirrors. 
     
     
       9. The apparatus of claim  7  in which each separate group includes at least a hundred micromirrors and each beam is incident on a separate group of channels.